Control Logix relay input/output cards

[Guest Guest_Jason]

Our plant has a spec. that everything must be pnp, however one of our process engineers bought a printer that I have to integrate that is npn, so I am going to have to buy some relays and then some i/o cards from AB. I know AB makes a relay output card for control logix, but do they make a relay input card. I have never done anything like this, so I am a little lost at where to start.

[b_carlton 61]

You may wish to try an interposing relay to do the logic shift. AB's 700-HL series are DIN rail maount and are only 1/4 inch wide. It may be cleaner that way.

[Guest Guest_Jason]

I got some input from a rep. and he is telling me to use solid state devices to do this, due to the cylce life of relays, or the relay output cards. I am looking at firing these relays approx. 700,000 per year, with a likely increase over the next couple of years. I am not sure what to do or exactly what I should purchase to do this. What I have is a printer that has npn i/o and we typcially use pnp, but I am being forced to use this printer. I am thinking I need to buy a sinking input card for the outputs from the printer, and then either a relay output card, npn compatible, for the inputs into the printer, but if I go solid state what would I need? Any help is appreciated.

[mgvol 0]

For the inputs, use a 1756-IB16I, isolated dc input module (can be configured for sinking or sourcing inputs). For the outputs use a 1756-OB8EI, electronically-fused & isolated (can also be configured for sinking or sourcing). Both modules are solid-state.

[Guest Guest_jason]

Thanks for your input, I am going to order the cards you suggested.